8,993 research outputs found
Dihadron correlations in PbPb collisions at 2.76 TeV with CMS
Measurements of charged dihadron DeltaEta-DeltaPhi correlations from the CMS
collaboration are presented for PbPb collisions at a center-of-mass energy of
2.76 TeV per nucleon pair over a broad range of pseudorapidity and the full
range of azimuthal angle. A significant correlated yield is observed for pairs
of particles with small DeltaPhi but large longitudinal separation DeltaEta,
commonly known as the "ridge". The ridge persists up to at least |DeltaEta| = 4
and the dependence of the ridge region shape and yield on collision centrality
and transverse momentum has been measured. A Fourier analysis of the long-range
two-particle correlation is presented and discussed in the context of higher
order flow coefficients.Comment: Proceedings of presentation given at Quark Matter 201
LHC Coverage of RPV MSSM with Light Stops
We examine the sensitivity of recent LHC searches to signatures of
supersymmetry with R-parity violation (RPV). Motivated by naturalness of the
Higgs potential, which would favor light third-generation squarks, and the
stringent LHC bounds on spectra in which the gluino or first and second
generation squarks are light, we focus on scenarios dominated by the pair
production of light stops. We consider the various possible direct and cascade
decays of the stop that involve the trilinear RPV operators. We find that in
many cases, the existing searches exclude stops in the natural mass range and
beyond. However, typically there is little or no sensitivity to cases dominated
by UDD operators or LQD operators involving taus. We propose several ideas for
searches which could address the existing gaps in experimental coverage of
these signals.Comment: 41 pages, 12 figures; v2: included new searches (see footnote 10),
minor corrections and improvement
Search for a heavy Higgs boson decaying to a pair of W bosons in proton-proton collisions at 13 TeV
A search for a heavy Higgs boson in the mass range from 0.2 to 3.0 TeV,
decaying to a pair of W bosons, is presented. The analysis is based on
proton-proton collisions at 13 TeV recorded by the CMS experiment
at the LHC in 2016, corresponding to an integrated luminosity of 35.9
fb. The W boson pair decays are reconstructed in the 22 and
2q final states (with e or ). Both gluon fusion and
vector boson fusion production of the signal are considered. Interference
effects between the signal and background are also taken into account. The
observed data are consistent with the standard model (SM) expectation. Combined
upper limits at 95% confidence level on the product of the cross section and
branching fraction exclude a heavy Higgs boson with SM-like couplings and
decays up to 1870 GeV. Exclusion limits are also set in the context of a number
of two-Higgs-doublet model formulations, further reducing the allowed parameter
space for SM extensions.Comment: Replaced with the published version. Added the journal reference and
the DOI. All the figures and tables can be found at
http://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-17-033
(CMS Public Pages
Top Quark Couplings and Search for New Physics at the LHC
The search for new physics in top quark decays at the LHC is reviewed in this
paper. Results from ATLAS [1] and CMS [2] experiments on top quark decays within the
Standard Model are presented together with the measurements of the W boson polarizations
and the study of the structure of the W tb vertex. As a natural step forward, the experimental
status on measurements sensitive to top quark couplings to gauge bosons (γ, Z, W and H) is
reviewed as well as possible top quark decays Beyond the Standard Model (MSSM and FCNC)
Photon-tagged jet measurements in Pb+Pb collisions with the CMS detector
Presented are the results of a detailed study for a complete simulation of
the CMS detectors at the LHC in view of the expected modification of jet
fragmentation functions in central Pb+Pb collisions at (s_NN)**0.5=5.5 TeV
compared to the vacuum (p+p) case. The study is based on photon-jet events,
using the correlation between isolated high-transverse energy (E_T>70 GeV)
photons and fully reconstructed jets, based on the information provided by the
CMS calorimeters and silicon tracker.Comment: 4 pages, 4 figures, ontribution to QM'08 conferenc
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